8. Effects of anxiety

• Anxiety has a negative effect on recall (weapon focus)

  • Anxiety creates physiological arousal in the body which prevents us paying attention to important cues, so recall is worse
  • When witnesses focus on a weapon, anxiety is created reducing recall for details of an event
  • Johnson and Scott did research on this with pps believing they were in a lab study
  • Group 1 -> low anxiety condition, casual convo in next room, man walked past with pen and grease on his hand
  • Group 2 -> high anxiety condition, heated argument in next room, sound of broken glass, man walked out holding a knife covered in blood
• Findings of Johnson and Scott

  • The tunnel theory of memory argues that people have enhanced memory for central events
  • 49% of pps recognised the man with the pen
  • 33% of pps recognised the man with the knife
• Anxiety has a positive effect on recall

  • The fight or flight response is triggered, increasing alertness. This may improve memory for the event as we become more aware of cues in the situation
  • Yuille and Cutshall conducted a study of an actual gun shooting in a shop in Canada - 21 witnesses with 13 in the study
  • Interviewed 4-5 months after the incident and were compared to original interviews at the time of the shooting - accuracy measured by number of details reported
  • Witnesses were asked to rate how stressed they felt at the time of the incident and any emotional problems
• Findings of Yuille and Cutshall

  • Little change in accuracy
  • Those who reported highest levels of stress were most accurate
• Explaining the contradictory findings

  • Yerkes-Dodson Law
  • Lower levels of anxiety/arousal produce lower levels of recall accuracy but when anxiety increases, memory becomes more accurate
  • However, there is an optimal level of anxiety whereby if a person experiences any more arousal, then their recall suffers a drastic decline
• Strength - evidence for anxiety having a positive effect on recall

  • Christianson et al. interviewed 58 witnesses to actual bank robberies in Sweden - some were directly involved and some indirectly
  • Researchers assumed those who were directly involved would experience the most anxiety - recall was 75% accurate across all witnesses, direct victims were even more accurate
  • Findings from actual crimes confirm that anxiety does not reduce the accuracy for recall of eyewitnesses and may even enhance it
• Counterpoint - Christianson et al. study

  • Interviewed pps several months after the event but they had no control over what happened to them in the intervening time eg. post-event discussion
  • The effects of anxiety may have been overwhelmed by these other factors and impossible to access by the time the pps were interviewed
  • Lack of confounding variables may be responsible for these findings, invalidating their support
• Strength - evidence supporting the view that anxiety has a negative effect on the accuracy of recall

  • Valentine study supporting research on weapon focus - used an objective measure (heart rate) to divide pps into high and low anxiety groups
  • Anxiety clearly disrupted the pps ability to recall details about the actor in the London Dungeon's Labyrinth
• Limitation - Johnson and Scott may have not tested anxiety

  • The reason pps may have focused on the weapon because they were surprised at what they saw rather than scared
  • Pickel conducted an experiment using scissors, a handgun, a wallet or raw chicken as hand held items in a hairdressing salon video - eyewitness accuracy was significantly poorer in the high unusualness conditions (chicken and handgun)
  • Suggests weapon focus effect is due to unusualness rather than anxiety/threat